Answer:
The correct answer is C) gene flow
Explanation:
The biological species concept defines what is a species. It says that a species is a group of individuals in a population that interbreed with each other. So there should be gene flow between the members of the population to come under species.
Appearance does not define that two individual are of same species because even different species can look same for example Western meadowlarks and eastern meadowlarks looks identical to each other but they do not interbreed so there is no gene flow between them so they are not same species.  
Therefore the primary criteria for determining species boundaries is gene flow.
 
        
             
        
        
        
primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide.
        
             
        
        
        
Answer:
During metaphase, each of the 46 chromosomes line up along the center of the cell at the metaphase plate.
Explanation:
 
        
             
        
        
        
The root system, the roots can store energy, anchor the plant to the ground and other surfaces, and they also adsorb and "drink" nutrients and vitamins from the soil. Remember to check yourself.
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Answer:
The event that happens in photosystem I is that electrons are transferred to ferredoxin
Explanation:
 This is a part of photosynthetic light reactions which makes use of light energy to transfer electrons from plastocyanin to ferredoxin.
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